Table 1.
Diagnoses of patients in 120-kVp (protocol A) and 80-kVp (protocol B and protocol C).
Table 2.
CT scanning parameters and postprocessing algorithms of protocol A, B, and C.
Figure 1.
Conventional transverse pancreas CT perfusion images.
(A) Protocol A (120-kVp, filtered back projection) in a 48-year-old female patient. Images from a 66-year-old female patient showing a cystic lesion in the head of the pancreas (arrow), with (B) protocol B (80-kVp, filtered back projection), and (C) protocol C (80-kVp, iDose4), which show region of interests (ROIs) manually drawn on aorta (ROI 1), subcutaneous fat of anterior abdominal wall (ROI 2), pancreas (ROI 3-5), liver (ROI 6-9), paraspinal muscle (10,11). For all measurements of the same patients, size, shape, and position of ROIs were kept constant by applying copy-and-paste function at workstations.
Figure 2.
Functional perfusion CT color maps of normal pancreatic tissue in a 48-year-old female.
(A) Transverse CT image. (B-D) CT perfusion parametric maps for blood flow, blood volume, and permeability-surface area product. Regions of interest (ROIs) drawn on pancreatic head (ROI 1), body (ROI 2), and tail (ROI 3). For all measurements of the same patient, size, shape, and position of ROIs were kept constant by applying copy-and-paste function at workstations.
Table 3.
Characteristics of patients in 120-kVp (protocol A) and 80-kVp (protocol B and protocol C).
Table 4.
Characteristics of patients with normal pancreas in 120-kVp (protocol A) and 80-kVp (protocol B and protocol C).
Table 5.
Subjective image quality scores for protocols A, B, and C from the two radiologists (reader 1 and reader 2).
Table 6.
Contrast-to-noise ratio (CNR), image noise and radiation dose for protocols A, B, and C.
Figure 3.
Bar graph of perfusion CT parameters of normal pancreas in the three protocols.
Blood flow (BF), blood volume (BV), and permeability-surface area product (PS). Means (standards deviations) are indicated in the figure.
Table 7.
Measurements of blood flow (BF), blood volume (BV), and permeability-surface area product (PS) in three protocols with normal pancreas.